sertulariadyE : sertularia. 71 



Polypidom three inches high, rigid, pinnate, lanceolate, dusky or 

 blackish-brown, varnished. Stalk straight, roundish, jointed, with 

 a series of alternate cells on each side : pinnae alternate, close, bifa- 

 rious, several originating from each space between the joints of the 

 stalk, simple, narrow at their origins, filiform, or almost insensibly 

 incrassated upwards, often gangrened at the apex. The cells are 

 arranged in a close row along each margin, and directed alternately 

 to opposite sides, so that they are almost quadrifarious, and the 

 pinna is hence quadrangular : they are very small, tubular, short 

 and adnate, with a wide mouth having a small tooth on the outer 

 edge. (Fig. 10, c.) Vesicles unilateral, superior, pearshaped, sub- 

 pedicellate, smooth. (Fig. 11.) 



9. S. PINASTER, pinnate; cells in opposite pairs, tubular, 

 the upper half divergent, with a plain rim ; vesicles oval, 

 quadrangular above, with a mucro at each angle on the tojJ, and 

 in the middle a little tubulous opening. W, Thompson. 



Sertularia pinaster, EUis and Solarid. Zooph. 5.5, tab. G, fig. 6, b. Rees Cyclop. 

 Vermes, pi. 8, fig. 4. W. Tho?npson in Ann. Nat. Hist. x. 23 ; and in Rep. Brit. 

 Assoc. 1843,283. — Dynamena pinaster, Lamour. Expos. Math. 12, tab. 6, fig. b. b. 



Hah. — " This species exactly as represented by Ellis, and bearing 

 vesicles, has been dredged by Mr, Hyndman at the entrance to Bel- 

 fast bay. By similar means this gentleman obtained it on two oc- 

 casions from a depth of 40 fathoms off Sana Island on the western 

 coast of Scotland ; but the few examples were without vesicles, as 

 was a single specimen dredged off the Mull of Galloway by Captain 

 Beechey, R.N., from a depth of 110 to 140 fathoms. In some in- 

 stances, a single plume ; in others, several plumes spring from the 

 same base. The branches are more produced than represented by 

 Ellis and Solander ; and in one specimen secondary branches are 

 thrown out, as we see in luxuriant examples of its near allies, S. 

 abietina and S. filicula." W. Thompson. 



Polypidom affixed by a creeping fibre, three or four inches in height, 

 pinnate, simple or with irregular shoots that appear rather to grow 

 on the rachis of another than to grow out of it : rachis straight, 

 serrulate, often plain towards the base, dusky or horn-coloured, 

 compressed : pinnae alternate, simple, rarely compound, patent : 

 Cells geminate, tubular, the lower half adhering close to the stalk, 

 the upper portion suddenly divergent, bent upwards so as to be 

 somewhat concave on the superior side, while there is a sort of fold 



